Frequency Selective Radome Design Based On Lattice Structure

The radome is a structure that protects the antenna from working normally.It must be able to withstand the harsh external environment in terms of mechanical properties and have good electromagnetic wave penetration characteristics in electrical performance.The Frequency Selective Surface(FSS)is a spatial filter that has selective characteristics for electromagnetic waves of different frequencies.The frequency selective radome studied in this paper produced by applying a frequency selective surface to the radome can make the electromagnetic wave of the own antenna pass normally,and the enemy detect electromagnetic waves of other frequencies being reflected in other directions,so that the antenna realizes electromagnetic stealth.The frequency selective radome has a variety of structures when designed,and different structures have different mechanical and electrical properties.The lattice structure is a new structure that has just been proposed in the 21 st century.This structure has the characteristics of high specific strength,high specific stiffness and light weight.This paper introduces the lattice structure into the design of the frequency selective radome can improve the mechanical performance of the radome while reducing the weight of the radome,which is of great significance.In this paper,two frequency-selective radomes are designed based on the lattice structure,which all achieve a passband in the S-band,and the transmittance is over 80%.Make the transmission coefficient of the entire X-band less than-10 dB.The bandpass radome designed based on lattice structure has high wave transmission characteristics and the wave transmission rate up to 94%.The band-stop radome has the characteristics of a wide passband,which enables the entire S-band to be a passband,and the wave transmission rate is above 80%.The main research contents of this paper include:Firstly,the design principle of the lattice structure frequency selective radome is studied,including the basic principle and design method of FSS and the establishment of lattice structure model and its wave-transmission rate analysis.In the analysis of the transmittance of the lattice structure,the effects of skin thickness,skin dielectric constant and core dielectric constant on the wave-transmissivity of the lattice structure were studied in turn.The dielectric constant of the skin and core layer and the skin thickness of the lattice structure were determined according to the research results.Then the lattice structure frequency selective radome was designed.Firstly,the design flow of the lattice structure frequency selective radome is studied,and then the band pass and band stop radome are designed separately.The equivalent circuit model of the design unit is given when designing the unit,and the performance of the radome during single-layer loading and multi-layer loading is analyzed.Finally,the characteristics of the designed radome are analyzed,including the influence of the cell size and the influence of different polarization modes and different incident angles on the characteristics of the radome.Finally,the performance of the two lattice structure frequency selective radomes was verified by the joint simulation of the antenna and the radome.Firstly,two kinds of array antennas working in S-band and X-band are designed respectively.Then,the two array antennas were jointly simulated with two kinds of radomes respectively.Finally,the results of the joint simulation are analyzed.The simulation results show that the designed lattice structure frequency selective radome has good wave-transmission in the S-band,which can make the antenna work normally,and has good stop-band characteristics in the X-band,which meets the design requirements.